Dec 28 (Reuters) - The interest rate on the most common type of U.S. home loan fell for a ninth straight week this week to close out the year at their lowest level since May, according to data released Thursday by Freddie Mac.

The interest rate on a 30-year fixed-rate mortgage averaged 6.61% as of Dec. 28, down from 6.67% a week earlier. The rate has declined each week since hitting the highest level in 22 years in late October, tumbling 1.18 percentage points in that span.

Rates, which had tumbled to below 3% during the height of the COVID-19 pandemic, had surged starting in 2022 when the Federal Reserve began an aggressive rate hiking campaign to rein in inflation.

The Fed recently signaled that it is done with rate hikes and is likely to start lowering them in 2024. Bond markets have responded with a ferocious end-of-year rally that has brought yields on the 10-year Treasury note used to set mortgage rates to below 4% from around 5% in late October. (Reporting By Dan Burns)